It's not available in the latest kernel just yet, but if you just so happen to have gotten your hands on a USB 3.0 device you want to use at full spectrum (you lucky jerk) or want to do this for the sake of geekiness, it's now possible to get USB 3.0 support for Debian and Ubuntu systems. The USB 3.0 subsystem will be integrated into the Linux kernel "soon," but if you've got some time on your hands, instructions have been provided to do it yourself.